A Retrospective Serological Study on Leptospira spp. Exposure and Brucella canis in Dogs from Croatian Animal Shelters

Authors

  • I. Reil Laboratory for Bacterial Zoonoses and Molecular Diagnosis of Bacterial Diseases, Department of Bacteriology and Parasitology, Croatian Veterinary Institute, 10000 Zagreb, Croatia Author https://orcid.org/0000-0002-2198-557X
  • S. Špičić Laboratory for Bacterial Zoonoses and Molecular Diagnosis of Bacterial Diseases, Department of Bacteriology and Parasitology, Croatian Veterinary Institute, 10000 Zagreb, Croatia Author https://orcid.org/0000-0001-8317-5831
  • S. Duvnjak Laboratory for Bacterial Zoonoses and Molecular Diagnosis of Bacterial Diseases, Department of Bacteriology and Parasitology, Croatian Veterinary Institute, 10000 Zagreb, Croatia Author https://orcid.org/0000-0002-1308-267X
  • M. Dopuđ Laboratory for Bacterial Zoonoses and Molecular Diagnosis of Bacterial Diseases, Department of Bacteriology and Parasitology, Croatian Veterinary Institute, 10000 Zagreb, Croatia Author https://orcid.org/0009-0009-0495-9861
  • M. Benić Laboratory for Mastitis and Raw Milk Quality, Department of Bacteriology and Parasitology, Croatian Veterinary Institute, 10000 Zagreb, Croatia Author https://orcid.org/0000-0001-7594-520X
  • T. Zajec Dumovec Shelter for Abandoned Animals of the City of Zagreb, 10361 Dumovec, Croatia Author
  • K. Lučić Dumovec Shelter for Abandoned Animals of the City of Zagreb, 10361 Dumovec, Croatia Author
  • A. Hampamer Friends Čakovec Shelter for Abandoned Animals, 40000 Čakovec, Croatia Author
  • M. Zdelar-Tuk Laboratory for Bacterial Zoonoses and Molecular Diagnosis of Bacterial Diseases, Department of Bacteriology and Parasitology, Croatian Veterinary Institute, 10000 Zagreb, Croatia Author https://orcid.org/0000-0002-9349-6177

DOI:

https://doi.org/10.46419/cvj.57.6.1

Keywords:

Leptospira spp., Brucella canis, shelter dogs, serological survey, seroprevalence, Croatia

Abstract

This retrospective cross-sectional study investigated exposure to Leptospira spp. and Brucella canis in dogs housed in two animal shelters in Croatia. Archived serum samples from 375 dogs from the Dumovec shelter (Zagreb County) and the Friends Čakovec shelter (Međimurje County) were tested. Specific antibodies against Leptospira were detected by the microscopic agglutination test (MAT) using a panel of ten pathogenic serovars, while B. canis antibodies were screened using a rapid immunochromatographic assay. Associations with shelter, sex, age, serovar distribution, and antibody titers were statistically evaluated. Overall, 128/375 dogs (34.1%) were seropositive to at least one Leptospira serovar. Seropositivity was 29.6% in Dumovec and 36.1% in Čakovec, with no significant difference between shelters. No significant association was found between overall seropositivity and sex or age. Before adjustment for recent vaccination, the most frequent MAT reactions were directed against antigens representing Icterohaemorrhagiae, Australis, Canicola, Pomona, and Grippotyphosa. In a vaccination-related sensitivity analysis, MAT reactivity to antigens representing Australis, Pomona, and Grippotyphosa remained frequent, although this pattern should be interpreted cautiously because complete vaccine-product information was not consistently available. Most antibody titres were low to moderate, more consistent with previous exposure rather than with acute infection. No antibodies against B. canis were detected in any samples. These findings indicate substantial environmental exposure of shelter dogs in Croatia to pathogenic leptospires and support their role as sentinels of zoonotic risk. The predominance of MAT reactivity patterns associated with serogroups linked to wildlife and rodent reservoirs highlights the need for continued surveillance, rodent control, and careful interpretation of serology in relation to vaccination history.

Downloads

Published

2026-11-15

Issue

Vol. 57 No. 6 (2026)

Section

Articles

License

Creative Commons License

This work is licensed under a Creative Commons Attribution 4.0 International License.

You are free to:

Share — copy and redistribute the material in any medium or format for any purpose, even commercially.

Adapt — remix, transform, and build upon the material for any purpose, even commercially.

The licensor cannot revoke these freedoms as long as you follow the license terms.

Under the following terms:

Attribution — You must give appropriate credit , provide a link to the license, and indicate if changes were made . You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use.

No additional restrictions — You may not apply legal terms or technological measures that legally restrict others from doing anything the license permits.